Family and friends of an 11-year-old girl who died under mysterious circumstances were trying Monday to find answers to the tragedy.

The girl, identified by family members as Martha Guzmán, lived with her mother in the 800 block of Northwest Fourth Street in Little Havana.

Paramedics responded to a call Sunday night from the house, where they found Martha unconscious and not breathing. She was rushed to the hospital in critical condition. She died shortly afterward.

Florida Department of Children and Families confirmed that “there is an ongoing investigation” involving the family and that there was another probe 10 years ago but did not offer more details.

Martha’s grieving father, Jorge Guzmán, arrived from Jacksonville Monday morning, but was unable to get information about his daughter’s death.

“I want to know who did this and why,” Guzmán said. “My daughter was only 11. How is it possible? Who would want to do this to my daughter?” Guzmán said in tears. “I can’t believe it. She was my life.”

José Navas, Guzmán’s brother who accompanied him to Martha’s home Monday, said his brother tried to call Martha Sunday night “but she wasn’t answering her phone,”

Navas said his brother then tried to contact Amaury Alvarenga, the girl’s mother. When she returned home from a coin laundry, she found her daughter unresponsive and bleeding. She called 911. Alvarenga was taken to a local hospital in a state of shock, according to Navas.

Araceli Andino, who lives in the same building, said her daughter Shelly and Martha were growing up together. She added that her daughter saw cuts on Martha’s arms.

“Maybe she felt lonely,” Andino said. The child lived with her mother and partner, Miguel Ruiz, and the couple have a 1-year-old son together, Andino said.

Martha studied at Lincoln-Martí School where she had just finished sixth grade.

On Monday afternoon, in the modest two-story apartment surrounded by crime scene tape, young children who said they went to school with Martha lingered around the area, not quite understanding what had happened to their classmate.

“We are extremely saddened by this tragedy,” said the private school’s founder, Demetrio Pérez. “It has affected everybody in our school community. We are very sorry for the family.”